Accuracy of diffusion-weighted magnetic resonance imaging in the diagnosis of cholesteatoma

Abstract

Objectives. Recent interest has focused on various MRI techniques as a way of evaluating patients with cholesteatoma both pre- and post-mastoidectomy.1,2 The aim of this study is to determine the role of diffusion-weighted MRI imaging in detecting primary and recurrent cholesteatoma, and its accuracy in differentiating cholesteatoma from granulations and inflammatory tissue. Methods. We have designed a prospective pilot study evaluating whether diffusion-weighted MRI imaging can accurately distinguish cholesteatoma from inflammatory tissue and fluid within the middle ear and mastoid cavity. We have established a database of consecutive patients placed on the waiting list for mastoidectomy and compared the preoperative reports with the perioperative findings during mastoidectomy. Outcomes were the presence or otherwise of cholesteatoma. Results. Between April and December 2007, 15 patients underwent preoperative ECHO planar MRI imaging and tympanomastoidectomy. Cholesteatoma was identified in six patients at time of surgery. This had been identified preoperatively on diffusion MRI scanning in five patients. In nine patients who did not have cholesteatoma at time of surgery all had negative preoperative scans. The MRI scans had a sensitivity and specificity of 83% and 100%, respectively. Conclusions. We have demonstrated that diffusion-weighted MRI imaging may be useful in the diagnosis and confirmation of cholesteatoma. In particular, a negative diffusion-weighted scan can almost certainly exclude the presence of cholesteatoma. This technique may be particularly valuable following canal-wall up mastoid surgery thus avoiding the requirement for a second-look procedure, on those patients whose postoperative hearing thresholds are satisfactory and do not require ossiculoplasty. References. 1 Vercruysse J.P., De Foer B., Pouillon M. et al. (2006) The value of diffusion-weighted MR imaging in the diagnosis of primary acquired and residual cholesteatoma: a surgical verified study of 100 patients. Eur. Radiol. 16, 1461–1467 2 Stasolla A., Magluilo G., Parrotto D. et al. (2004) Detection of postoperative relapsing/residual cholesteatoma with diffusion-weighted echo-planar magnetic resonance imaging. Otol. Neurotol. 25, 879–884